Aalto University

About: Aalto University is a education organization based out in Espoo, Finland. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 9969 authors who have published 32648 publications receiving 829626 citations. The organization is also known as: TKK & Aalto-korkeakoulu.

Planck 2013 results. XXIV. Constraints on primordial non-Gaussianity

Abstract: The Planck nominal mission cosmic microwave background (CMB) maps yield unprecedented constraints on primordial non-Gaussianity (NG). Using three optimal bispectrum estimators, separable template-fitting (KSW), binned, and modal, we obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result fNLlocal = 2.7 ± 5.8, fNLequil = -42 ± 75, and fNLorth = -25 ± 39 (68% CL statistical). Non-Gaussianity is detected in the data; using skew-Cl statistics we find a nonzero bispectrum from residual point sources, and the integrated-Sachs-Wolfe-lensing bispectrum at a level expected in the ΛCDM scenario. The results are based on comprehensive cross-validation of these estimators on Gaussian and non-Gaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are confirmed by skew-Cl, wavelet bispectrum and Minkowski functional estimators. Beyond estimates of individual shape amplitudes, we present model-independent, three-dimensional reconstructions of the Planck CMB bispectrum and thus derive constraints on early-Universe scenarios that generate primordial NG, including general single-field models of inflation, excited initial states (non-Bunch-Davies vacua), and directionally-dependent vector models. We provide an initial survey of scale-dependent feature and resonance models. These results bound both general single-field and multi-field model parameter ranges, such as the speed of sound, cs ≥ 0.02 (95% CL), in an effective field theory parametrization, and the curvaton decay fraction rD ≥ 0.15 (95% CL). The Planck data significantly limit the viable parameter space of the ekpyrotic/cyclic scenarios. The amplitude of the four-point function in the local model τNL< 2800 (95% CL). Taken together, these constraints represent the highest precision tests to date of physical mechanisms for the origin of cosmic structure.

How to Construct Deep Recurrent Neural Networks

Abstract: In this paper, we explore different ways to extend a recurrent neural network (RNN) to a \textit{deep} RNN. We start by arguing that the concept of depth in an RNN is not as clear as it is in feedforward neural networks. By carefully analyzing and understanding the architecture of an RNN, however, we find three points of an RNN which may be made deeper; (1) input-to-hidden function, (2) hidden-to-hidden transition and (3) hidden-to-output function. Based on this observation, we propose two novel architectures of a deep RNN which are orthogonal to an earlier attempt of stacking multiple recurrent layers to build a deep RNN (Schmidhuber, 1992; El Hihi and Bengio, 1996). We provide an alternative interpretation of these deep RNNs using a novel framework based on neural operators. The proposed deep RNNs are empirically evaluated on the tasks of polyphonic music prediction and language modeling. The experimental result supports our claim that the proposed deep RNNs benefit from the depth and outperform the conventional, shallow RNNs.

Organizational Culture and Effectiveness: Can American Theory Be Applied in Russia?

Abstract: This paper examines the link between organizational culture and effectiveness for foreign-owned firms operating in Russia. Beginning with a model of organizational culture developed in the USA, the paper presents a multi-method analysis of culture and effectiveness in a transition economy. We argue that effectiveness in Russia relies more on adaptability and flexibility than in the USA. Furthermore, the legacy of the communist era forces firms in Russia to deal with a workforce with a unique time perspective and a unique set of sub-cultures that often undermine attempts at coordination and integration. We first explore these ideas using survey data on 179 foreign-owned firms operating in Russia and compare the results to those obtained for firms in the USA. We then present four case studies designed to ground the results in the Russian context, and to document cultural dynamics not captured by the model.

Decomposing the value of department store shopping into utilitarian, hedonic and social dimensions: Evidence from Finland

Abstract: – The purpose of this paper is to decompose total customer value as perceived by department store shoppers into utilitarian, hedonic and social dimensions, and empirically test this conceptualization in a Finnish department store shopping context., – Data were collected by a questionnaire administered over three days at a department store that generates the second largest turnover in Finland. A total of 364 shoppers completed the questionnaire., – Empirical evidence supports our tripartite conceptualization of total customer value. In particular, social value is an independent construct. Further, social value varies by day‐of‐week, with a significant increase on Saturday (versus weekdays) when the store is more crowded, whereas no such differences in utilitarian and hedonic values were detected., – The principal contribution is a tripartite conceptualization of total customer value that incorporates utilitarian, social and hedonic value dimensions in a department store shopping context. Individually these dimensions are all well rooted in streams of consumer behavior literature, albeit mostly at the product or brand, not the store, level. Increasing our understanding of these softer aspects of shopping, particularly the social dimension, is important because they represent possible differentiating factors in the highly competitive and often commoditized retail markets.

Thin perfect absorbers for electromagnetic waves: Theory, design, and realizations

Abstract: In recent years we have learned to fabricate structures smaller than electromagnetic wavelengths, and to assemble them into metamaterials with exotic optical properties for previously unimaginable applications. One such property is perfect absorption of incident light, with no reflection or transmission, across many wavelengths. The authors review the physics, design principles, and classification of thin perfect absorbers, and outline avenues for progress.